As the liquid crystal display technology matures, a liquid crystal display device available in the market has gradually developed in a large-size direction. However, at a technical level, a large-sized display panel needs to overcome limitations of a viewing angle. Hence, a wide-viewing-angle liquid crystal display technology has been proposed.
Currently, depending on their display modes, liquid crystal panels may include a twisted nematic (TN) type one, an in-plane switching (IPS) type one, and an advanced super dimension switch (ADS) type one. For the liquid crystal panel with the ADS display mode, a multi-dimensional electric field is formed by means of electrical fields generated at edges of electrodes within an identical plane and an electrical field generated between an electrode layer and a plate electrode layer, so as to enable all the liquid crystal molecules between the electrodes and right above the electrodes to rotate. As compared with the liquid crystal panel with the IPS display mode, the liquid crystal panel with the ADS display mode can improve the operational efficiency of the liquid crystal molecules and enhance the light transmission efficiency. The liquid crystal panel with the ADS display mode has such advantages as high image quality, high resolution, high transmittance, low power consumption, wide viewing angle, high aperture ratio, low chromatic aberration and being free of push Mura.
FIG. 1 is a schematic view showing an arrangement mode of electrodes at an identical electrode layer in an existing display panel with the ADS display mode. Two auxiliary regions 1 and 2 are defined in a pixel region, and electrodes 70 parallel to each other are arranged in the auxiliary regions 1 and 2, respectively. An angle between the electrodes 70 in the auxiliary region 1 and the electrodes 70 in the auxiliary region 2 is 90°, and all the electrodes 70 extend in their own directions. An electric field El perpendicular to the electrodes 70 is generated by means of a voltage between the electrodes 7, so as to excite liquid crystal molecules 21.
In order to prevent refractive index anisotropy of a liquid crystal layer and a liquid crystal thickness from being varied along with a tilted viewing angle, usually there is an angle of 90° between an initial alignment direction of the liquid crystal molecules 21 in the auxiliary region 1 and that in the auxiliary region 2. When a voltage is applied to the liquid crystal display device, the liquid crystal molecules 21 rotate in an identical direction, and after the rotation, the angle between the alignment directions is still maintained, as shown in FIG. 2.
However, in the coplanar liquid crystal display device with the structure as shown in FIG. 1, before applying a deflection voltage, the liquid crystal molecules in the liquid crystal layer are in the initial alignment directions under action of an alignment film attached onto the display device, respectively. There is an angle of 90° between the initial alignment direction of the liquid crystal molecules in the auxiliary region 1 and that in the auxiliary region 2. However, as shown in FIG. 2, the liquid crystal molecules at a boundary between the auxiliary regions 1 and 2 are affected by the alignment films corresponding to the auxiliary regions 1, 2 and aligned at different angles, so the alignment directions of the liquid crystal molecules at the boundary are uncertain. When in transition from the alignment direction in the auxiliary region 1 to the alignment direction in the auxiliary region 2 at the boundary, the liquid crystal molecules at the boundary may rotate in different directions. Hence, a “disclination point” (shown by “x” in FIG. 3) is generated at the boundary as shown in FIG. 3, which results in uneven display brightness and the occurrence of Mura. Especially, when the “disclination points” are located at special positions or distributed unevenly, the brightness of the display device will be affected in a more apparent manner.